Abnormality determination method and abnormality determination device of grid interconnection system

摘要

PROBLEM TO BE SOLVED: To implement, with a simple configuration, accurate control with respect to continuous operation without performing parallel-off of a power conversion device when a disturbance of an AC power system occurs in a system interconnection system.SOLUTION: Noise component removal means 12 generates a correction phase variation component &Dgr;&thetas;' by removing a noise component from a phase variation component &Dgr;&thetas; extracted from system power supply voltage by phase variation component extraction means 11; ramp rate limitation means 13 generates a limitation-granted phase variation component &Dgr;&thetas;ramp by granting ramp rate limitation to the correction phase variation component; and subtraction means 14 generates a FRT determination index &Dgr;&thetas;" by subtracting the limitation-granted phase variation component from the correction phase variation component. Jump frequency calculation means 15 generates a jump frequency component from the FRT determination index; and jump phase calculation means 16 generates a jump phase component from the FRT determination index. Isolated operation determination means 17 determines an isolated operation state on the basis of the jump frequency component and the jump phase component.SELECTED DRAWING: Figure 1